Examples of the conventionally-known method for sewing an ornamental chord material onto a sewing workpiece include loop sewing in which the cord material is sewn onto the sewing workpiece in a loop configuration and cord sewing in which the cord material is extended above and over the sewing workpiece and sewn onto the sewing workpiece as if adhered onto and along the upper surface of the sewing workpiece. In performing the loop sewing and the cord sewing, it was heretofore necessary to attach respective dedicated guide devices. Therefore, in order to change from one of the loop sewing and the cord sewing to the other, it was necessary to attach and detach the guide devices, which resulted in poor operating efficiency. To avoid such an inconvenience, a guide device has been proposed which can be used both for the loop sewing and the cord sewing as disclosed in Patent Literature 1.
The guide device disclosed in Patent Literature 1 is constructed to be attached or mounted to an end portion of a machine head frame, and the sewing machine is constructed in such a manner that a cord material is sewn by use of one of a plurality of needle bars, provided on the machine head frame, which is located on the end portion having the guide device mounted thereto. More specifically, in the loop sewing, the guide device forms a loop of the cord material by a loop holder of the guide device moving downward or descending in response to descending of the needle bar and releases the cord material by the loop holder moving upward or ascending by a resilient force of a coil spring in response to ascending of the needle bar. A height of the loop in the loop sewing is adjustable by changing a height of an adjusting bolt screwed to the upper end of an ascending/descending shaft. Further, when the cord sewing is to be performed, the loop holder is replaced with a cord holder, and a cord presser, provided at the distal end of the cord holder, holds the cord on the sewing workpiece by the resilient force of the coil spring.
However, the guide device disclosed in Patent Literature 1 does itself have a complicated mechanical mechanism. Thus, the technique disclosed in Patent Literature 1 encounters the inconvenience that the guide device having such a complicated mechanical mechanism has to be attached to the sewing machine. Furthermore, because the guide device disclosed in Patent Literature 1 is constructed to be attached to one end portion of the machine head frame, only one needle bar located at the end portion to which the guide device is mounted can be used for the sewing of the cord material. With such a conventionally-known structure, only up to two guide devices can be mounted to the machine head frame, one to each of the left and right ends of the machine head frame, as a result of which only two types of cord materials at most can be sewn. Furthermore, when the height of the loop sewing is to be adjusted, a mechanical adjusting operation of turning the adjusting bolt is required, and thus, the loop height adjustment tends to require time and labor.